While some scientists have drawn a link between COVID-19 and the recent emergence of a rare inflammatory syndrome in children, some media reports and officials have overstated the certainty and nature of that link.
“We know that we don’t have all the data yet on this and it’s important that we actually prove causation before we definitively try and discuss this link,” said Dr. Amesh A. Adalja, an infectious disease expert at Johns Hopkins Center for Health Security.
“I would not be surprised if there is a link, but it hasn’t been proven yet,” he told NTD in an interview.
The New York State Department of Health is investigating 102 cases of the syndrome, similar to the rare Kawasaki Disease, causing inflammation in the skin, eyes, blood vessels, and hearts.
It has killed three young children in New York. Other regions, such as Italy, have also seen an increase in children presenting these symptoms.
Adalja said it’s possible “there is some sort of mechanism between the two that possibly coronavirus infection sets off an inflammatory cascade that results in [the inflammatory syndrome in children.”
But since the inflammatory syndrome has not occurred consistently throughout the pandemic but has instead appeared to spike recently, this suggests another factor may be at play, Adalja said. Not all cases of the syndrome have coincided with exposure to the Chinese Communist Party (CCP) virus, which causes COVID-19.
‘Manifestation of the COVID Virus’
Some journalists have stated the causal relationship between COVID-19 and the syndrome as a certainty.
NBC News New York reported that “the number of children known to be developing a dangerous response to COVID-19 appears to be going up.” CNBC published an article titled, “Coronavirus inflammatory syndrome is causing heart and kidney failure in some NYC kids.”
The New York Times reported that “any sense of relief” that children have been largely spared by COVID-19 “was shattered this week when a 5-year-old in New York City died from the” inflammatory syndrome. The article thus suggests the syndrome was directly caused by COVID-19.
New York Governor Andrew Cuomo has also made statements that assume a definite causal link. On May 13, he called the syndrome “a new manifestation of the COVID virus.”
Anne Rowley, a professor of pediatrics, microbiology and immunology at Northwestern University’s Feinberg School of Medicine, told RT news: “It’s not clear whether the cases are caused by the same process, or whether some are caused by COVID-19 and some by another condition, such as toxic shock syndrome, which is [the result of] a bacterial infection.”
The causes of Kawasaki Disease have not been well-understood in the past either. “It might be linked to genes, viruses, bacteria, and other things in the world around a child, such as chemicals and irritants,” states a WebMD article on the disease. “The disease probably isn’t contagious, but it sometimes happens in clusters in a community.”
Most cases are treatable. Symptoms include a long-lasting fever, rash, swelling, and red eyes.
What the Scientists Have Said
The Centers for Disease Control issued a health advisory on May 14 with the title, “Pediatric Multi-System Inflammatory Syndrome Potentially Associated with COVID-19.” It noted that “many” of the patients who have had symptoms of the syndrome have also tested positive for COVID-19.
It noted that it is as yet uncertain whether the syndrome only affects children.
Although many with the syndrome have also tested positive for COVID or COVID antibodies, 13 percent tested negative for COVID, according to the New York State Department of Health.
A correspondence in the medical journal The Lancet (pdf), published May 6, detailed the cases of eight children who had severe inflammation. Some tested positive for COVID-19 or had likely exposure to the virus, while some did not.
A study published by Italian doctors in The Lancet on May 13 interpreted a strong link between the syndrome and COVID-19. It found a 30-fold increase in the disease starting March 17, compared to the previous five years.
Though the increase was great, the actual number of cases was not large. In the previous five years, 19 children had been diagnosed. Between March 17 and April 14, 2020, ten children had been diagnosed.
The study found that the recent cases tended to be more severe than in the past.
Based on the 30-fold increase, the doctors wrote in their interpretation that the COVID-19 “epidemic was associated with high incidence of a severe form of Kawasaki disease.”
Correlation, Not Necessarily Causation
The Royal College of Paediatrics and Child Health in the United Kingdom described the syndrome as “temporally associated with COVID-19.” This characterization stresses that the two conditions are happening at the same time, and that is the limit of the proven association thus far.
A case study (pdf) on a 6-month-old infant diagnosed with Kawasaki Disease who tested positive for COVID-19 was pre-published in the journal Hospital Pediatrics on April 6. An editorial (pdf) from the same journal cautioned against jumping to conclusions about causation.
The editorial cites the term apophenia, which is a human tendency to seek patterns in random information. The journal notes that while this can be useful, “we are sometimes misled by these patterns,” and “objective and thorough investigations are needed to confirm our observations.”
The article points to two challenges facing the connection between COVID and the syndrome. One is that Kawasaki Disease does not have a definitive diagnosis. The other is that all the media attention surrounding the syndrome may cause doctors to diagnose more patients with Kawasaki Disease than they would have previously.
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